| 摘要 |
A process for the preparation of chiral alpha-hydroxycarboxylic acids: in which R1 is optionally halogen substituted C1-C2-alkyl and R2 is optionally halogen substituted C2-C3-alkyl from a compound: in which R'2 is optionally halogen substituted C2-C3-alkylene, m is 0 or 1 and R is optionally substituted alkyl, aryl, heteroaryl or heterocyclyl and X can be oxygen, sulfur, sulfinyl, sulfonyl, imino, C1-C6-alkylimino, xanthate, silyl, or, if m is equal to 0, halogen, which is reacted in the presence of a cyanide group donor to give the corresponding (R)- or (S)-cyanohydrin or its racemate: which then is converted by means of acidic hydrolysis into an acid: or its racemate, and by cleavage of the group: (R)m-X (V), and optional resolution, whereby the desired chiral alpha-hydroxycarboxylic acid of the formula (I) is obtained.
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